public SQLParserContext(string sentence)
{
StringCollection words = new StringCollection();
sentence = sentence.Replace("\r", " ").Replace("\n", " ");
sentence = sentence.Trim();
int curPos = 0;
for (int i = 0; i < sentence.Length; i++)
{
//忽略空字符
while (i < sentence.Length && (sentence[i] == ' ' || sentence[i] == ' '))
{
i++;
}
curPos = i;
//分析字符串
if (sentence[i] == '\'')
{
for (i++;;)
{
if (i < sentence.Length && sentence[i] != '\'')
{
i++;
}
else if (i + 1 < sentence.Length && sentence[i] == '\'' && sentence[i + 1] == '\'')
{
i += 2;
}
else
{
break;
}
}
words.Add(sentence.Substring(curPos, i - curPos + 1));
}
else
{
while (i < sentence.Length && sentence[i] != ' ' && sentence[i] != ' '&& Operators.IndexOf(sentence[i]) < 0)
{
i++;
}
if (i > curPos)
{
words.Add(sentence.Substring(curPos, i - curPos));
}
if (i < sentence.Length && Operators.IndexOf(sentence[i]) >= 0)
{
words.Add(sentence[i].ToString());
}
}
}
for (int i = 0; i < words.Count; i++)
{
ParserToken t = new ParserToken();
if (string.Compare(words[i], "select", true) == 0)
{
t.Word = "select";
t.Type = ParserTokenType.KEYWORD;
}
else if (string.Compare(words[i], "from", true) == 0)
{
t.Word = "from";
t.Type = ParserTokenType.KEYWORD;
}
else if (string.Compare(words[i], "where", true) == 0)
{
t.Word = "where";
t.Type = ParserTokenType.KEYWORD;
}
else if (i + 1 < words.Count && string.Compare(words[i], "group", true) == 0 && string.Compare(words[i + 1], "by", true) == 0)
{
t.Word = "group by";
t.Type = ParserTokenType.KEYWORD;
i++;
}
else if (string.Compare(words[i], "having", true) == 0)
{
t.Word = "having";
t.Type = ParserTokenType.KEYWORD;
}
else if (i + 1 < words.Count && string.Compare(words[i], "order", true) == 0 && string.Compare(words[i + 1], "by", true) == 0)
{
t.Word = "order by";
t.Type = ParserTokenType.KEYWORD;
i++;
}
else if (words[i] == "(" || words[i] == ")")
{
t.Word = words[i];
t.Type = ParserTokenType.OPERATOR;
}
else if (words[i] == ",")
{
t.Word = words[i];
t.Type = ParserTokenType.SEPARATOR;
}
else
{
t.Word = words[i];
t.Type = ParserTokenType.IDENTIFY;
}
tokenList.Add(t);
TokenPosition = 0;
}
}
public void PopClause()
{
if (clauseStack.Count > 0)
{
SQLParserClause clause = clauseStack.Pop() as SQLParserClause;
string clauseStr = "";
while (clause.Tokens.Count > 0)
{
ParserToken t = clause.Tokens.Dequeue() as ParserToken;
string prestr = " ";
if (clauseStr.Length > 0)
{
char l = clauseStr[clauseStr.Length - 1];
char f = t.Word[0];
if (NoSeperators.IndexOf(l) >= 0 || NoSeperators.IndexOf(f) >= 0)
{
prestr = "";
}
}
else
{
prestr = "";
}
clauseStr += prestr + t.Word;
}
if (clauseStr.Trim().Length > 0)
{
string prestr = " ";
if (tempClause.Length > 0)
{
char l = tempClause[tempClause.Length - 1];
char f = clauseStr[0];
if (NoSeperators.IndexOf(l) >= 0 || NoSeperators.IndexOf(f) >= 0)
{
prestr = "";
}
}
else
{
prestr = "";
}
tempClause += prestr + clauseStr;
prestr = " ";
if (parenthesesClause.Length > 0)
{
char l = parenthesesClause[parenthesesClause.Length - 1];
char f = clauseStr[0];
if (NoSeperators.IndexOf(l) >= 0 || NoSeperators.IndexOf(f) >= 0)
{
prestr = "";
}
}
else
{
prestr = "";
}
parenthesesClause += prestr + clauseStr;
prestr = " ";
if (expClause.Length > 0)
{
char l = expClause[expClause.Length - 1];
char f = clauseStr[0];
if (NoSeperators.IndexOf(l) >= 0 || NoSeperators.IndexOf(f) >= 0)
{
prestr = "";
}
}
else
{
prestr = "";
}
expClause += prestr + clauseStr;
}
if (clause.Type == SQLParserClauseType.PARENTHESES)
{
parenthesesLevel--;
if (parenthesesLevel == 0 && tempLevel == 2 && parenthesesClause.Trim().Length > 0)
{
Parentheses.Add(parenthesesClause.Trim());
}
}
if (clause.Type == SQLParserClauseType.EXPRESSION)
{
expressionLevel--;
if (expressionLevel == 0 && expClause.Trim().Length > 0)
{
if (tempLevel == 1)
{
Expressions.Add(expClause.Trim());
}
else if (tempLevel == 3)
{
if (groupByListLevel == 1)
{
GroupByExps.Add(expClause.Trim());
}
else if (orderByListLevel == 1)
{
OrderByExps.Add(expClause.Trim());
}
}
}
}
if (clause.Type == SQLParserClauseType.COUNT)
{
tempLevel--;
}
if (clauseStack.Count <= 3)
{
switch (clause.Type)
{
case SQLParserClauseType.SELECT:
SelectClause = tempClause.Trim();
break;
case SQLParserClauseType.FROM:
FromClause = tempClause.Trim();
break;
}
}
if (clauseStack.Count <= 7)
{
switch (clause.Type)
{
case SQLParserClauseType.WHERE:
WhereClause = tempClause.Trim();
break;
case SQLParserClauseType.GROUPBYLIST:
groupByListLevel--;
GroupByList = tempClause.Trim();
break;
case SQLParserClauseType.HAVING:
HavingClause = tempClause.Trim();
break;
case SQLParserClauseType.ORDERBYLIST:
orderByListLevel--;
OrderByList = tempClause.Trim();
break;
}
}
}
}
